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Discussion Starter · #1 ·
I want to share my experiences conducting a test with RAID configuration on my MDD 867. This afternoon I finished a rather grueling 2 days of tests to determine the truth about RAID arrays and a few options many of us have under OS X. Following is a brief outline of the methods used and subsequent real world results.

1/ Using the OS X software RAID configured through Disk Utility, I reformatted my 2 drives and set them up as a striped array. After installing half a dozen of my most commonly used apps (InDesign, PhotoShop, Illustrator, Retrospect...), I noticed a marked performance improvement. All apps opened significantly quicker and the OS responded a little faster. Copying files showed a decrease in time of about 10% to 15% overall. Boot times were not significantly improved. Without spending a dime, I would recommend this effort to anyone having more than one hard drive installed, along with a good back up strategy, such as an external or spare drive. The next time you have to reformat, give it a try. You won't be disappointed.

Now for the GOOD stuff!

2/ Installed Sonnet's Tempo RAID133 ATA dual channel controller ($199 U.S.), carefully followed their concise installation instructions, including another reformatting of the drives and VOILA! Simply installing OS X clearly indicated a definite speed bump was to follow. Because this hardware RAID scheme was to be my eventual goal, I waited to test the performance until I had installed ALL my apps and files. After launching and relaunching most of my most commonly used apps, I can attest to the fact that this configuration is the best money one could spend to produce significant performance increases. Although boot times only decreased marginally, every app I tried launched in less than half the time as my factory non-RAID configuration. Any file I chose opened VERY quickly. Copying files took approx. 30% less time and the best measure was when I restored some large (5GB to 20GB) Retrospect back up files. On my G4/400 at home, decompression and transfer rates topped out at 130MB per minute. The factory spec MDD at the office (the test machine) performed the same task at 180MB per minute. Once the software RAID was configured, that number rose to 200MB. But after the hardware RAID, it shot up to 300MB+ per minute! PhotoShop on the factory setting launched in about 25 to 30 seconds, 20 in software RAID and 10 seconds with the hardware config. Mail now opens in 2 seconds! Safari - 4 seconds. InDesign - 7 seconds. PhotoShop - 10 seconds.

I have kept a written log of more test times, if anyone is interested.

Bottom line - hardware RAID via the Sonnet card works... and VERY well!!! I'd bet my MDD 867 is at LEAST as fast as a new MDD 1.42, if not faster.

Test system specs - MDD 867, 2 x 60GB hard drives, 2GB RAM
 

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That's great! I have the Sonnet ATA 66 RAID card and I have had nothing but great performance/luck with it! Truly a top notch product.

Just an FYI, there is another product coming to market. It's from a company called acard . They have a 4 channel IDE Raid Aray card coming out for Mac OS X.

Thanks for the info though. good stuff!
 

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First thing to do with ata drives is to make sure they have 8 meg caches as the performance gains are significant.
There are lots of potential "bottlenecks" in getting actual drive speed increases.
Barefeats does extensive testing.
http://www.barefeats.com/fire36b.html
The downside is that recovering a failed Level O RAID is almost impossible so you have higher risks.
Certainly users with large PS files that go beyond their RAM limitations - say those 300+ meg files will see significant gains if the array is used for scratch.

We've had a 4 stripe array on an ultrascsi 320 get into the 200+ category but that sucker cost $3k to put together 18 months ago :eek:
These days triple stripe 18 gig Ultra scsi on a 320 card is a reasonable price and less likely to fail than 3 or 4 atas yet will top 200 megs per second.
It's the failure rate on ata drives that scares me off ata raids especially when a singel 8 meg cache drive can get into 70 read and 55 write. That's very good speed for most users and the second drive can be used for backup or a mirror.
Still it's good fun and X makes setting up a breeze. Just keep in mind backup is REALLY needed - a corrupted directory on a RAID = :(

The 8 meg cache drive marked the first time I didn't miss ultra scsi in day to day work.
A single current top end drive will fully saturate the internal bus on all G4s prior to the MDD series so that's a good and cheap starting point for speed bumping - use your old drive for backup. :D



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Well, the forthcoming acard from acard.com promises 0+1 Raid level capabilities on a 4 channel independent IDE hardware card.

This, combined with the 8Meg onboard drive cache should ensure that users get both the performance, cheaper cost by using the cheaper IDE drives as well as the security of mirrored drives across a stripe level 0.

If you watch the trends in the industry, everyone is getting away from SCSI drives in RAID sets as the performance of IDE quickly increases and the costs are much cheaper.

Three of the big companies that come to mind are Apple's XServe and XRaid, Openstorage Raid Sets, and ATAboy Raid sets.

once again SCSI is still the powerhouse, but even that is beginning to falter a little, especially on the consumer level workstations.
 

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Discussion Starter · #5 ·
macdoc,

I couldn't agree with you more on the virtues of backing up! After a catastrophic drive failure within the first 6 months of my business, I've been a diehard proponent of good back up strategies. Retrospect backs up my client files and "Home" folder daily to an external d2 Firewire HD and to CD weekly. I'll be adding a third internal HD next week for a little extra "redundancy".
 

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